Winter 2022-2023 Summary – Fourth Warmest on Record

Blue Hill Observatory
Winter 2022-2023 Summary:

The 2022-2023 winter (December-February) season was generally very warm with a few cold periods and with near average precipitation and much below average snowfall and sunshine. The approximated 24-hour mean temperature for the winter of 34.0 deg F was 6.5 degrees warmer than the 130-year winter average and 4.3 degrees warmer than the 1991-2020 30-year mean, and the season was the fourth warmest winter on record. The average maximum temperature was 41.6 deg F, which was 4.3 deg F warmer than the 30-year normal and also the fourth warmest on record. The average minimum temperature was 26.7 deg F, which was 5.8 deg F warmer than the 30-year normal and the third warmest on record. Each of the three months was warmer than average, but January stood out as the second warmest on record. The warmest days during winter included a high temperature of 63F on December 30th, which was a new record for the date, and 61F on February 16th. The low temperature on February 16th was 50F, which tied as the warmest daily minimum temperature for that date and for the entire month of February. The coldest day during winter was February 4th, which was the coldest period of a brief, two-day outbreak of pure Arctic air that brought a low temperature of -14F, a high temperature of 14F, and wind chill temperatures as low as -40F on that date. The reading of -14F on February 4th and the low of -11F on February 3rd were both new records for those dates, and the former was the coldest temperature at Blue Hill since the same value was observed on February 14th, 2016. Of the 90 winter days, 64 of them were warmer than normal, including all but one day in January, and 18 winter days had high temperatures of 50F or more. Liquid equivalent precipitation for winter totaled 14.56 inches, which was slightly more than the 30-year normal of 13.89 inches. Both December and January were wetter than average, and February was very dry until the last week of the month. The largest precipitation event brought a storm total of 2.42 inches of rain over two days from December 15th-17th. Precipitation was most frequent during January with 20 days of measurable precipitation during that month, which tied the record for January previously set in 1950, and this number was among the most recorded for any month of the year. In addition, there were twelve consecutive days with measurable precipitation on January 12th-23rd, which had never before occurred in January. Snowfall was below average during each month, and the winter snowfall total of 24.3 inches was more than two feet below the 30-year normal of 49.4 inches for winter. The largest single-event snowfalls during winter were 4.1 inches on January 23rd, which followed more than an inch of rain, and 4.0 inches on February 22nd-23rd, which was accompanied by sleet and a trace of freezing rain. After a relatively snowless start to February, winter finished with 9.2 inches over the last eight days. Following a recent trend, the local ponds froze over and partly or fully thawed several times during the winter months. Ponkapoag Pond initially froze on December 25th, and Houghton’s Pond initially froze on December 27th. Both ponds were ice and snow covered at the end of February. The mean wind speed for the winter months was only 12.7 mph, which was the second lowest on record for any December-February period. The peak gust during winter was 74 mph from the southeast during rain and warm temperatures ahead of a strong Arctic cold front that brought a rapid drop in temperature on December 23rd. The afternoon of that day also brought the lowest barometric sea-level pressure during winter of 29.04 inches. The highest sea-level pressure for the season of 30.54 inches was observed just 31 hours earlier on the morning of December 22nd. Winter sunshine was much below average with 348.5 hours, or 41 percent of the possible bright sunshine, which was seven percent less than the long-term mean for winter. After a relatively sunny December with 54 percent of the possible sunshine, January was the least sunny on record with only 26 percent of the possible sunshine, and February was slightly below average with 45 percent of the possible bright sunshine. The winter total sunshine was the lowest observed in the last thirty years.

BHO Warmest Winter (Dec-Feb) Approximated 24-Hour Mean Temperature, deg F (1885-1886 to 2022-2023):

1) 34.9 in 2015-2016
2) 34.8 in 2001-2002
3) 34.3 in 2011-2012
4) 34.0 in 2022-2023
5) 32.9 in 2016-2017
6) 32.7 in 2019-2020
7) 32.6 in 1997-1998
8) 32.3 in 1936-1937
   32.3 in 1998-1999

BHO Warmest Winter (Dec-Feb) Average Maximum Temperature, deg F (1885-1886 to 2022-2023):

1) 43.3 in 2015-2016
2) 42.7 in 2011-2012
3) 42.5 in 2001-2002
4) 41.6 in 2022-2023
5) 40.7 in 1936-1937
   40.7 in 1990-1991
7) 40.6 in 1889-1890
8) 40.5 in 2016-2017

BHO Warmest Winter (Dec-Feb) Average Minimum Temperature, deg F (1885-1886 to 2022-2023):

1) 28.0 in 2001-2002
2) 27.2 in 2015-2016
3) 26.7 in 2022-2023
4) 26.5 in 2011-2012
5) 26.2 in 1997-1998
6) 25.7 in 2016-2017
7) 25.6 in 2019-2020
8) 25.2 in 1948-1949

BHO Lowest Winter (Dec-Feb) Mean Wind Speed, mph (1885-1886 to 2022-2023):

1) 12.2 in 2020-2021
2) 12.7 in 2022-2023
3) 12.8 in 2019-2020
   12.8 in 2021-2022
5) 13.1 in 2013-2014
   13.1 in 2018-2019
7) 13.3 in 2011-2012
   13.3 in 2014-2015
   13.3 in 2017-2018

Mike Iacono
Chief Scientist
Blue Hill Observatory